System and Method for Guiding Medical Instruments

ABSTRACT

A system is disclosed. The system contains an instrument configured to fit in a patient&#39;s anatomy, an optical sensor associated with the instrument, a processing unit receiving data from the optical sensor, and a display displaying position of the instrument in the patient&#39;s anatomy based on the data from the optical sensor.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/296,220, filed on Feb. 17, 2016, which is incorporated herein byreference in its entirety.

FIELD

The present invention relates to field of medical devices. Moreparticularly, the present invention relates to a system and method ofguiding medical instruments.

BACKGROUND

Many different types of procedures are performed by dentists and dentalsurgeons using hand-held and hand-guided instruments to alter existinganatomy such as hand-pieces to operate rotary instruments (burrs, files,grinding wheels), and surgical tools that cut with emission of light(lasers) or electricity (cauterizing instruments) on teeth, facialbones, and soft tissues on patients. These procedures require skill andcare to prevent damage to surrounding anatomical structures and hosttissues. The procedures are often difficult to carry out because of thelimited amount of space within the mouth of the patient's oral cavitythat restricts the ability of the practitioner to align or move the toolduring the course of the procedure. Frequently, the operating site isdifficult to reach or to see, and nerves and blood vessels as well ascortical plates present additional challenges of not being easilyidentifiable during these procedures. Other factors such as patientmovement can affect the precision and orientation of the tool withrelation to the desired direction, and the precision of the surgicalintervention.

The insertion of endosseous dental implants is an example of a procedurethat illustrates the problem. Dental implant surgery involves placing animplant device, such as one or more artificial root replacements, in thejawbones of patients. Such devices must be precisely placed within theosseous supporting structures for the best implant survival, both interms of success rates as well as quality of outcome. Precise placementof the endosseous device requires suitable preparation of the implantreceptor site with respect to surrounding hard- and soft tissues. Theentire final rehabilitation is typically comprised of a root replacement(the dental implant), an implant abutment, and a prosthetic replacementtooth, (or in combination of the two as a single piece), either assingle tooth, multiple implants and teeth for a bridge in a partiallyedentulous patient, or a full arch bridge supported by multiple implantsfor full arch of teeth. During the surgical osteotomy preparation tocreate the bed for the implant to be inserted, great care must be takento avoid causing injury to the patient. Injury may be caused by, forexample, inadvertent entry into the mandibular nerve canal, inadvertententry into the sinuses, perforation of the cortical plates, damage toadjacent teeth, or other damage known in the art.

In general there is a growing need to be able to provide systems thatwill reduce the risks associated with procedures carried out usingdental instruments, as well as to improve outcome by idealizing implantlocation, and to maximize length, diameter and trajectory of the device.These new guiding systems must provide the surgeon with real timeinformation that enables him/her to accurately guide his/herinstrument(s).

Presently disclosed embodiments address the limitations known in theart.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts anatomical image of a patient's Computed Tomography (CT)scan rendered in planning software according to some embodimentspresently disclosed.

FIGS. 2a-b depict an embodiment according to the present disclosure.

FIG. 3 depicts another embodiment according to the present disclosure.

FIGS. 4a-b depict another embodiment according to the presentdisclosure.

FIGS. 4c-f depict other embodiments according to the present disclosure.

FIGS. 5-6 depict multiple views of the patient's anatomy for providing adoctor with a real time feedback of the instrument and drill positionaccording to the present disclosure.

FIG. 7 depicts another embodiment according to the present disclosure.

In the following description, like reference numbers are used toidentify like elements. Furthermore, the drawings are intended toillustrate major features of exemplary embodiments in a diagrammaticmanner. The drawings are not intended to depict every feature of everyimplementation nor relative dimensions of the depicted elements, and arenot drawn to scale.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth toclearly describe various specific embodiments disclosed herein. Oneskilled in the art, however, will understand that the presently claimedinvention may be practiced without all of the specific details discussedbelow. In other instances, well known features have not been describedso as not to obscure the invention.

Computed Tomography (CT) based dental 3D imaging is becoming an integralcomponent to achieving success in dental procedures/surgeries. It canaid in treatment planning and clinically sound placement of, forexample, implants and to avoid major critical structure such as inferioralveolar nerve or sinus. In planning a dental procedure/implant, adoctor creates a virtual plan based on the CT image data of a patient.

FIG. 1 illustrates an exemplary anatomical image of a patient's CT scanrendered in planning software, according to some embodiments presentlydisclosed. According to some embodiments, a patient's anatomical image102 such as CT scan image is rendered in three dimensions using aplanning software 101 on a computer display 120 of a computer 215 (shownin FIG. 2b ). The planning software 101 allows the doctor to visualizethe patient's anatomy in a virtual space and create a virtual plan. Inthe virtual plan, the doctor is able to place one or more virtualimplants 103 at exact desired locations within patient's anatomy.According to some embodiments, the planning software 101 also rendersother objects 104 such as abutments and planned final restorations,together with the trajectory of the implants. According to someembodiments, the planning software 101 also renders vital structuressuch as a mandibular nerve 106 and provides/depicts spatial relationshipbetween the mandibular nerve 106, virtually placed implants 103 andother objects 104 with the patient's anatomy. This establishes thethree-dimensional final plan of the virtual implants 103 and objects104. According to some embodiments, information such as trajectory,distances between objects, vital anatomical structures can be calculatedand displayed to the doctor using, for example, the planning software101.

According to some embodiments, an optical-based tracking systempresently disclosed comprises an optical sensor coupled with a dentalinstrument, for example, a drill. In some embodiments, the opticalsensor is configured to send data to a computer running algorithms thatcompare the exact location of teeth or markers in previously obtaineddicom files from a CT scan to the surface anatomy of the patient's teethor markers. In some embodiments, the navigation algorithm is configuredto process the data from the optical sensor and calculatethree-dimensional (3D) location of the dental instruments in patient'smouth. In some embodiments, the navigation algorithm is configured toshow real-time positioning of the dental instrument with respect to thevirtual plan. In some embodiments, the navigation algorithm tracks theposition of the instrument in reference to the patient anatomy and sendsvisual feedback to doctor in real time.

According to some embodiments, an optical-based tracking system 200presently disclosed is shown in FIG. 2a . According to some embodiments,the optical-based tracking system 200 comprises an optical sensor 210.According to some embodiments, the optical sensor 210 is coupled withdental instrument 213.

According to some embodiments, the dental instrument 213 is a drill.According to some embodiments, the drill 213 has a hand piece 230 couplewith the optical sensor 210. According to some embodiments, the opticalsensor 210 is coupled with the hand piece 230. According to someembodiments, the optical sensor 210 is part of the housing of the handpiece 230. According to some embodiments, the hand piece 230 acceptsvarious burrs 235 of different diameters and lengths. According to someembodiments, the hand piece 230 accepts various burrs 235 of differentdiameters and lengths for preparing, for example, an osteotomy at aplanned implant site of the patient. According to some embodiments, thevarious burrs 235 used during preparation of the site are automaticallyrecognized and identified by the hand-piece 230 as such. According tosome embodiments, the display 120 depicts the selected burr, with allits characteristics such as type, length and diameter.

According to some embodiments, the optical sensor 210 digitizes imagesof objects such as teeth or markers within an image plane 212, andtransmits the images to the computer 215 (shown in FIG. 2b ) running analgorithm to superimpose and merge the datasets obtained by the opticalsensor 210 and the previously obtained data sets of the CT scan in dicomformat. According to some embodiments, the computer 215 comprises adisplay 120 and one or more user input devices such as, for example, amouse 222 or a keyboard 223.

According to some embodiments, the optical sensor 210 is inserted into amouth of a patient (as shown in FIG. 3) and the imaging plane 212 ispassed over one or more intraoral structures 240 or markers (not shown)at a suitable distance to acquire surface scan/data from one or moreteeth or other markers. According to some embodiments, the one or moreintraoral structures 240 are one or more teeth, one or more crowns,and/or one or more implants in the patient's mouth. According to someembodiments, the markers (not shown) are one or more features placed bya doctor or another medical professional inside the patient's mouth tobe used as a reference by the optical sensor 210. According to someembodiments, the markers (not shown) are one or more removable featuresplaced by a doctor or another medical professional inside the patient'smouth to be used as a reference by the optical sensor 210.

According to some embodiments, the data set of the surface scan obtainedin the oral cavity is merged with the previously obtained CT data set inreal time. According to some embodiments, intra-oral structures 240 aresuperimposed using a surface algorithm onto the dicom data sets from thepatient's CT scan, resulting in a merged real time picture. As the drillbits 235 are recognized to their specific shape, size and diameter via adetection mechanism 241 incorporated into the dental instrument 213, theexact outline relevant to length and diameter is projected over theanatomic picture 102 of the patient. If no virtual planning was doneprior to treatment, virtual implants 103 will not be available. However,every one skilled in the art recognizes that although not plannedpreviously, anatomic structures such as the mandibular nerve 106 or thecortical plates 107 and adjacent teeth 108 are readily visible and canbe avoided. According to some embodiments, the virtual implants 103 havebeen planned in the planning software 101 and can be followed andsuperimposed with the real time image.

According to some embodiments, multiple different reformatted sectionsof the previously obtained dicom data sets are displayed on the computer120 such as, but not limited to, coronal, saggital and panoramicsections. Thus the surgeon in real time can guide the location of thedrill 235 to avoid adjacent anatomic structures such as nerves 106,adjacent teeth 108, cortical plates 107, and maxillary sinus amongstothers. Alternatively, the surgeon can follow the previously plannedvirtual implant location 103 in length, angulation, trajectory andultimately, final implant position.

According to some embodiments, communications between the computer 215and the optical sensor 210 may use any suitable communications linkincluding, for example, a wired connection or a wireless connectionbased upon, for example, IEEE 802.11 (also known as wireless Ethernet),BlueTooth, or any other suitable wireless standard using, e.g., a radiofrequency, infrared, ultrasound or other wireless communication medium.In medical imaging or other sensitive applications, wireless imagetransmission from the optical sensor 210 to the computer 215 may besecured. The computer 215 may generate control signals to the opticalsensor 210 which, in addition to image acquisition commands, may includeconventional camera controls such as focus or zoom.

According to some embodiments, the optical sensor 210 may acquiretwo-dimensional image sets at a video rate while the optical sensor 210is passed over a surface of the one or more intraoral structures 240 ormarkers (not shown). The two-dimensional image sets may be forwarded tothe computer 215 for derivation of three-dimensional point clouds.

The three-dimensional data for each newly acquired two-dimensional imageset may be derived and fitted or “stitched” to existingthree-dimensional data using a number of different techniques. Oneuseful example of such a technique is described in U.S. application Ser.No. 11/270,135, filed on Nov. 9, 2005, the entire contents of which isincorporated herein by reference. However, it will be appreciated thatthis example is not limiting, and that the principles described hereinmay be applied to a wide range of three-dimensional image capturesystems. It will also be understood that terms such as “video” or “videorate” imply a wide range of possible frame rates associated with suchvideo. While most modern video formats employ a frame rate of 25 to 30frames per second, early video employed frame rates as low as 8 framesper second, and movies of the early 1900's varied from 12 to 18 framesper second. In addition, it is common for specialized imaging equipmentto employ a rate adapted to the computational demands of particularimaging and rendering techniques, and some video systems operate withframe rates anywhere from 4 frames per second (for computationallyextensive imaging systems) to 100 frames per second or higher (forhigh-speed video systems). As used herein, the terms video rate andframe rate should be interpreted broadly. Notwithstanding this broadmeaning, it is noted that useful and visually pleasing three-dimensionalimaging systems have been constructed according to the foregoing withframe rates of at least ten frames per second, frame rates of at leasttwenty frames per second, and frame rates between 25 and 30 frames persecond.

It will be appreciated that the ability of certain systems, such asmulti-aperture camera systems, to derive three-dimensional data fromtwo-dimensional video image sets may depend in part on an ability toestablish correspondence of surface points between image pairs (ortriplets, and so on). The process of establishing point correspondencesmay be improved by identifying, within the processing system, uniquefeatures of the surface upon which correspondence may be based. Incertain aspects, distinguishing features of teeth at varying levels ofdetail may be employed to enhance this process. However, this processdepends on an ability to locate such distinguishable features. Theprocess of establishing point correspondences may also, or instead, beenhanced by the addition of optically detectable features thereto, whichmay be as simple as artificial black dots distributed over a white orrelatively light surface. In a dental context, this may be achieved witha spray, powder, mouth rinse, or the like that distributes opticallydetectable matter across the dentition or other dental object to bescanned. By randomly distributing such small, distinguishable dotsacross the surface, the likelihood of locating distinguishable featuresin a particular image set may be significantly improved, thus improvingthe speed and accuracy of the overall three-dimensional data acquisitionprocess.

From time to time in continuous or incremental data acquisition systems,the fitting or stitch between two frames may fail. In such situations, auser may be notified through visual feedback that a recover mode hasbeen entered. In the recover mode, the optical sensor 210 may seek toreacquire the previous scan by test fitting new scan data to previouslyacquired data, and providing visual feedback to a user to assist innavigating back to a scan location on the subject where there-acquisition is being attempted. In a related landing mode, a user mayattempt to initiate a new scan registered or connected to an existingthree-dimensional model. Similar visual feedback tools may be providedto guide a user to an appropriate scan location, and notify a user whenthe scan has been reacquired. These techniques are described in greaterdetail in U.S. application Ser. No. 11/383,623, filed on May 16, 2006,incorporated herein by reference in its entirety. Other suitabletechniques may be employed for navigation, controlling scan quality,analyzing scanned subject matter, and manipulating scanned models,various embodiments of which are described in greater detail below.

According to some embodiments, the display 120 may include any displaysuitable for video or other rate rendering at a level of detailcorresponding to the acquired data or a rendered version of the acquireddata. Suitable displays include cathode ray tube displays, liquidcrystal displays, light emitting diode displays, plasma displays, andthe like. In some embodiments, the display may include a touch screeninterface using, for example capacitive, resistive, or surface acousticwave (also referred to as dispersive signal) touch screen technologies,or any other suitable technology for sensing physical interaction withthe display 120. In addition, where three-dimensional visualization isdesired, the display 120 may include a three-dimensional display using awide variety of techniques including stereo pair imaging, holographicimaging, and multiplanar or volumetric imaging, each with a number ofrendering modalities that may be usefully employed with the systemsdescribed herein.

According to some embodiments, the optical sensor 210 may, through acontinuous acquisition process, capture a point cloud of surface datahaving sufficient spatial resolution and accuracy to calculatethree-dimensional (3D) surface points of the dental instrument 213 inpatient's mouth based on the previously obtained and reconstructed CTscan. According to some embodiments, three-dimensional (3D) coordinates205 may be obtained from data generated by the optical sensor 210.According to some embodiments, the coordinates 205 provide position andorientation represented in three-dimensional Cartesian coordinates (x,y, z) and orientation angles (azimuth, elevation, roll). According tosome embodiments, the optical sensor 210 transmits data to the computer215. According to some embodiments, the computer 215 is configured togenerate three-dimensional (3D) coordinates 205 for the optical sensor210 based on data from the optical sensor 210. According to someembodiments, the computer 215 is configured to generatethree-dimensional (3D) coordinates 205 for the dental instrument 213based on data from the optical sensor 210. According to someembodiments, three-dimensional (3D) coordinates for the dentalinstrument 213 correspond to the three-dimensional (3D) coordinates 205associated with the optical sensor 210.

According to some embodiments, the computer 215 is configured tocorrelate the three-dimensional (3D) coordinates 205 with the patient CTcoordinate system 105 and track position and orientation of the dentalinstrument 213 relative to the patient CT coordinate system 105.

According to some embodiments, the computer 215 is configured totransform the three-dimensional (3D) coordinates 205 to the patient CTscan coordinate system 105. According to some embodiments, thethree-dimensional coordinate 205 of a point or an object in thepatient's oral cavity can be represented in any coordinate system using,for example, a rigid body transformation matrix. For example, anatomicalstructure and other virtual objects such as implants in the patient'soral cavity can be transformed into the patient CT scan coordinatesystem 105, or vice versa.

According to some embodiments, the patient CT coordinate system 105 isused to track the dental instrument 213 during a surgery. In this case,any object represented in the coordinate system 205 is transformed intothe patient CT coordinate system 105. According to some embodiments, anyphysical object in a real space registered with respect to anycoordinate system can be represented by the three-dimensional coordinateas long as the relationship or the transformation matrix is known.

According to some embodiments, the coordinate system 205 may be definedby a distance between optical sensor 210 and one or more teeth,implants, static anatomical structure or artificial markers coupled toone or more teeth in the patient's oral cavity. The patient CTcoordinate system 105 established in CT scan data is defined by the CTscan imaging software. According to some embodiments, the position andorientation of the dental instrument 213 is transformed into the patientCT coordinate system 105. According to some embodiments, the opticalsensor 210 comprises a camera suitable for capturing images from which athree-dimensional point cloud may be recovered. For example, the opticalsensor 210 may employ a multi-aperture system as disclosed, for example,in U.S. Pat. Pub. No. 20040155975 to Hart et al., the entire contents ofwhich is incorporated herein by reference. While Hart discloses onemulti-aperture system, it will be appreciated that any multi-aperturesystem suitable for reconstructing a three-dimensional point cloud froma number of two-dimensional images may similarly be employed, includingsystems with moving apertures, fixed apertures, and/orelectro-mechanically shuttered apertures. According to some embodiments,the optical sensor 210 comprises a plurality of apertures including acenter aperture positioned along a center optical axis of a lens and anyassociated imaging hardware. According to some embodiments, the opticalsensor 210 comprises a stereoscopic, triscopic or other multi-camera orother configuration in which a number of cameras or optical paths aremaintained in fixed or moving relation to one another to obtaintwo-dimensional images of an object from a number of slightly differentperspectives. According to some embodiments, the optical sensor 210comprises suitable processing for deriving a three-dimensional pointcloud from an image set or a number of image sets, or eachtwo-dimensional image set may be transmitted to an external processorsuch as contained in the computer 215 described below. According to someembodiments, the optical sensor 210 comprises structured light, laserscanning, direct ranging (e.g., time of flight in a known direction), orany other technology suitable for acquiring three-dimensional data, ortwo-dimensional data that can be resolved into three-dimensional data.

FIG. 3 depicts an exemplary navigated surgical procedure, according tosome embodiments presently disclosed. According to some embodiments, thecomputer 215 receives data from the optical sensor 210. The computer 215matches the data sets from the CT scan and surface optical scan in realtime and provides visualization on the display 120 showing planningsoftware 101 for the doctor's visual feedback.

According to some embodiments, the system 200 is constantly updated onthe display 120 showing planning software 101 to provide the doctor witha real time feedback of the instrument and drill position via drilldetection mechanism 241 and orientation with respect to the patient'sanatomy 102, implants 103, and/or any other reference point. Thisprovides the doctor with a capability to visually track the position ofthe dental instrument 213 in the patient in real time. As the dentalinstrument 213 moves during a surgery, the position and orientation ofthe virtual instrument assembly 231 are updated in real time on thecomputer display showing planning software 101. During a surgery, if theaccuracy of the instrument tracking is determined to be unreliable dueto various factors, for example, the optical sensor 210 generatesunreliable data, the planning software 101 displays a warning message toinform the doctor. In some embodiments, the planning software calculatesand displays on the planning software 101 useful information for thedoctor during the surgery such as the position and orientation offsets,an error to the intended drill trajectory while drilling, a distance toa vital structure in the patient's anatomy.

According to some embodiments, the dental instrument 213 has a featurethat relays a feedback from the planning software, so the doctor doesnot have to look at the display showing planning software 101 and keepshis vision on the surgery. For example, the dental instrument 213 has avisual indicator, such as an LED light (not shown) or small LCD panel(not shown). The visual indicator provides the doctor with informationsuch as drilling accuracy being within a tolerance or simply a warningif drill is too close to a vital anatomy of the patient. According tosome embodiments, the dental instrument 213 has an audible feedback thatprovides an audible sound or haptic feedback that provides vibration ora tactile feedback to inform the doctor regarding the drilling accuracyor if drill is too close to vital anatomy of the patient.

According to some embodiments, the display 120 depicts multiple views ofthe patient's anatomy 102 to provide the doctor with a real timefeedback of the instrument and drill position as shown in FIGS. 5-6.

FIGS. 4a-b depict an exemplary procedure for registering dimensions ofthe dental instrument 213 according to some embodiments presentlydisclosed. For the dental instrument 213, a drill offset 802 from theoptical sensor 210 to the tip of an attached drill bit 503 must bedetermined to register the drill position and orientation within thepatient's oral cavity. According to some embodiments, a registrationapparatus 801 of known dimensions may be used to register the drilloffset 802. A drill bit 503 of the dental instrument 213 is insertedinto the socket 803 of the registration apparatus 801. Another sensor805 is attached to the registration apparatus 801 with a known positionoffset. The socket 803 has a physical stop that makes contact, with thedrill bit 503 when it is fully inserted. In this static position, thedrill 503's critical features (e.g., tip length, position andorientation) are determined from the position and orientation data fromthe optical sensor 210 and geometric calculation. During a surgery, thedrill bit 503 may be changed several times, and each drill bit may havea different length and size. According to some embodiments, the planningsoftware 101 supports this drill registration to determine the drillshape whenever a new drill bit is used. This allows the virtualinstrument assembly 601 to be accurately updated and the drill bitinformation is updated on the planning software 101 accordingly.

FIG. 4c depict another exemplary procedure for registering dimensions ofthe dental instrument 213 according to some embodiments presentlydisclosed. For the dental instrument 213, a drill offset 850 from theoptical sensor 210 to the tip of an attached drill bit 550 must bedetermined to register the drill position and orientation within thepatient's oral cavity. According to some embodiments, the drill bit 550comprises one or more markings 555 to identify the length, diameter,and/or type of drill bit inserted into the instrument 213. According tosome embodiments, the one or more markings 555 is a bars code. Accordingto some embodiments, the optical sensor 210 is configured to identifythe one or more markings 555 and identify the length, diameter, and/ortype of drill bit 550 inserted into the instrument 213. According tosome embodiments, the detection mechanism 241 is configured to identifythe one or more markings 555 and identify the length, diameter, and/ortype of drill bit 550 inserted into the instrument 213. According tosome embodiments, the detection mechanism 241 is an optical sensorconfigured to monitor the drill bit 550.

According to some embodiments, the drill bits have different shaftconfigurations that allow the presently described system to identify thelength, diameter and type of burr inserted into the instrument 213.FIGS. 4d-f depict top view of drill bits 560, 565 and 570. According tosome embodiments, the drill bits 560, 565 and 570 comprise one or moremarkings 575. According to some embodiments, the one or more markings575 are notches in the drill bits 560, 565 and 570. According to someembodiments, the one or more markings 575 are protrusions in the drillbits 560, 565 and 570. According to some embodiments, the presentlydescribed system is configured to identify the length, diameter and typeof the drill bits 560, 565 and 570 based on the dimensions, number ofand/or location of the one or more markings 575.

Referring to FIGS. 2a-b , according to some embodiments, the dentalinstrument 213 is a hand piece configured to accommodate various burrs235. According to some embodiments, the hand piece 230 accepts variousbits 235 of different diameters and lengths. According to someembodiments, the hand piece 230 accepts various bits 235 of differentdiameters and lengths for reducing volume of a tooth structure.According to some embodiments, the hand piece 230 accepts various bits235 of different diameters and lengths for reducing volume of a bone.According to some embodiments, the various burrs 235 used during aprocedure are automatically recognized and identified by the hand-piece230 as such (as described above). According to some embodiments, thedisplay 120 depicts the selected burr, with all its characteristics suchas type, length and diameter.

According to some embodiments, the optical sensor 210 is inserted into amouth of a patient (as shown in FIG. 7) and the imaging plane 212 ispassed over one or more intraoral structures 240 or markers (not shown)at a suitable distance to acquire surface scan/data from one or moreteeth or other markers. According to some embodiments, the one or moreintraoral structures 240 are one or more teeth, one or more crowns,and/or one or more implants in the patient's mouth. According to someembodiments, the markers (not shown) are one or more features placed bya doctor or another medical professional inside the patient's mouth tobe used as a reference by the optical sensor 210. According to someembodiments, the markers (not shown) are one or more removable featuresplaced by a doctor or another medical professional inside the patient'smouth to be used as a reference by the optical sensor 210.

According to some embodiments, the data set of the surface scan obtainedin the oral cavity is merged with the previously obtained CT data set inreal time. According to some embodiments, intra-oral structures 240 aresuperimposed using a surface algorithm onto the dicom data sets from thepatient's CT scan, resulting in a merged real time picture. As the bit235 is recognized to its specific shape, size and diameter via adetection mechanism as described above, the exact outline relevant tolength and diameter is projected over the anatomic picture 102 of thepatient. According to some embodiments, reduction of volume of the toothstructure 703 has been planned in the planning software 101 and can befollowed and superimposed with the real time image. According to someembodiments, the surgeon in real time can reduce the volume of the toothstructure 703 to match the planned structure represented in the planningsoftware 101.

FIG. 7 depicts an exemplary navigated surgical procedure, according tosome embodiments presently disclosed. According to some embodiments, thecomputer 215 receives data from the optical sensor 210. The computer 215matches the data sets from the CT scan and surface optical scan in realtime and provides visualization on the display 120 showing planningsoftware 101 for the doctor's visual feedback.

According to some embodiments, the system 200 is constantly updated onthe display 120 showing planning software 101 to provide the doctor witha real time feedback of the instrument and burr position via drilldetection mechanism 241 and orientation with respect to the patient'sanatomy 102, implants 103, and/or any other reference point. Thisprovides the doctor with a capability to visually track the position ofthe dental instrument 213 in the patient in real time. As the dentalinstrument 213 moves during a surgery, the position and orientation ofthe virtual instrument assembly 231 are updated in real time on thecomputer display showing planning software 101. During a surgery, if theaccuracy of the instrument tracking is determined to be unreliable dueto various factors, for example, the optical sensor 210 generatesunreliable data, the planning software 101 displays a warning message toinform the doctor. In some embodiments, the planning software calculatesand displays on the planning software 101 useful information for thedoctor during the surgery such as the position and orientation offsets,an error to the intended drill trajectory while drilling, a distance toa vital structure in the patient's anatomy.

According to some embodiments, the dental instrument 213 has a featurethat relays a feedback from the planning software, so the doctor doesnot have to look at the display showing planning software 101 and keepshis vision on the surgery. For example, the dental instrument 213 has avisual indicator, such as an LED light (not shown) or small LCD panel(not shown). The visual indicator provides the doctor with informationsuch as tooth structure volume removal accuracy being within a toleranceor simply a warning if the doctor is about to remove unnecessary part ofthe tooth structure. According to some embodiments, the dentalinstrument 213 has an audible feedback that provides an audible sound orhaptic feedback that provides vibration or a tactile feedback to informthe doctor regarding the tooth structure volume removal accuracy.

According to some embodiments, the optical-based tracking system 200further comprises an optical sensor-cleaning member (not shown).According to some embodiments, the optical sensor-cleaning member (notshown) is coupled with dental instrument 213. According to someembodiments, the optical sensor-cleaning member (not shown) isconfigured to spray gas to remove any debris that may be at leastpartially covering/blocking the optical sensor 210. According to someembodiments, the optical sensor-cleaning member (not shown) isconfigured to spray liquid to remove any debris that may be at leastpartially covering/blocking the optical sensor 210. According to someembodiments, the optical sensor-cleaning member (not shown) isconfigured to spray gas and/or liquid to remove any debris that may beat least partially covering/blocking the optical sensor 210. Accordingto some embodiments, the gas is air or compressed air. According to someembodiments, the liquid is water. According to some embodiments, thedebris is blood, bone, and/or any other matter present in the patientsmouth during procedure.

It is also understood that the registration of an instrument assemblycan be performed in a variety of ways using a sensor, a transmitter,and/or a combination of a sensor and a transmitter in a similar way asdescribed above without deviating the scope of the present subjectmatter.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contentclearly dictates otherwise. The term “plurality” includes two or morereferents unless the content clearly dictates otherwise. Unless definedotherwise, all technical and scientific terms used herein have the samemeaning as commonly understood by one of ordinary skill in the art towhich the disclosure pertains.

The foregoing detailed description of exemplary and preferredembodiments is presented for purposes of illustration and disclosure inaccordance with the requirements of the law. It is not intended to beexhaustive nor to limit the invention to the precise form(s) described,but only to enable others skilled in the art to understand how theinvention may be suited for a particular use or implementation. Thepossibility of modifications and variations will be apparent topractitioners skilled in the art. No limitation is intended by thedescription of exemplary embodiments which may have included tolerances,feature dimensions, specific operating conditions, engineeringspecifications, or the like, and which may vary between implementationsor with changes to the state of the art, and no limitation should beimplied therefrom. Applicant has made this disclosure with respect tothe current state of the art, but also contemplates advancements andthat adaptations in the future may take into consideration of thoseadvancements, namely in accordance with the then current state of theart. It is intended that the scope of the invention be defined by theClaims as written and equivalents as applicable. Reference to a claimelement in the singular is not intended to mean “one and only one”unless explicitly so stated. Moreover, no element, component, nor methodor process step in this disclosure is intended to be dedicated to thepublic regardless of whether the element, component, or step isexplicitly recited in the claims. No claim element herein is to beconstrued under the provisions of 35 U.S.C. Sec. 112, sixth paragraph,unless the element is expressly recited using the phrase “means for . .. ” and no method or process step herein is to be construed under thoseprovisions unless the step, or steps, are expressly recited using thephrase “step(s) for . . . .”

What is claimed is:
 1. A system comprising: an instrument configured tofit in a patient's anatomy; an optical sensor associated with theinstrument; a processing unit receiving data from the optical sensor;and a display displaying position of the instrument in the patient'sanatomy based on the data from the optical sensor.
 2. The system ofclaim 1, wherein the display further displays a Computed Tomography scandata of the patient.
 3. The system of claim 2, wherein the position ofthe instrument is displayed in relation to the Computed Tomography scandata of the patient.
 4. The system of claim 2, wherein the position ofthe instrument is merged with the Computed Tomography scan data of thepatient.
 5. The system of claim 1, wherein the processing unit generatesa warning signal of unreliable tracking of the instrument.
 6. The systemof claim 5, wherein the warning signal is one of an audible feedback, avisual feedback, and a haptic feedback.
 7. The system of claim 1,wherein the processing unit generates a warning signal when theinstrument in a wrong position.
 8. The system of claim 7, wherein thewarning signal is one of an audible feedback, a visual feedback, and ahaptic feedback.
 9. The system of claim 1, wherein the instrument is adental drill configured to fit in the patient's oral cavity.
 10. Thesystem of claim 9, wherein the processing unit determines position ofthe dental drill within the patient's oral cavity based on the datareceived from the optical sensor.
 11. The system of claim 1, wherein theprocessing unit generates a warning signal when the instrument is afirst distance away from a vital structure in the patient's anatomy. 12.The system of claim 11, wherein the warning signal is one of an audiblefeedback, a visual feedback, and a haptic feedback.
 12. The system ofclaim 11, wherein vital structure is one of a nerve, a blood vessel, acortex, and a sinus.
 13. The system of claim 1, wherein the firstdistance is determined prior to inserting the instrument in thepatient's anatomy.
 14. The system of claim 1, wherein the first distanceis about 2 millimeters.
 15. The system of claim 1, wherein theinstrument is configured to remove first volume of the patient's toothin the patient's oral cavity.
 16. The system of claim 15, wherein theprocessing unit determines position of the instrument within thepatient's oral cavity based on the data received from the opticalsensor.
 17. The system of claim 16, wherein the processing unitgenerates a warning signal when the instrument successfully removes thefirst volume of the patient's tooth.
 18. The system of claim 17, whereinthe warning signal is one of an audible feedback, a visual feedback, anda haptic feedback.
 19. The system of claim 15, wherein the first volumeis determined prior to inserting the instrument in the patient'sanatomy.
 20. A dental drill comprising: a detection mechanism; and anopening configured to accommodate a drill bit comprising one or moremarkings; wherein the detection mechanism is configured to determineinformation about the drill bit based on the one or more markings. 21.The dental drill of claim 20, wherein the detection mechanism is anoptical sensor.
 22. The dental drill of claim 20, wherein the one ormore markings is a bar code.
 23. The dental drill of claim 20, whereinthe information is a length of the drill bit, a diameter of the drillbit, or a type of drill bit.
 24. The dental drill of claim 20, whereinthe one or more markings is a notch.
 25. The dental drill of claim 20,wherein the one or more markings is a protrusion.
 26. A methodcomprising: receiving data from an optical sensor associated with aninstrument; calculating position of the instrument based on the datafrom the optical sensor; and displaying the position of the instrumenton a display.